In medical facilities, such as clinics and hospitals, a variety of modalities like those for CR (computed radiography), CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography) and ultrasonography, have been widely used for capturing images of anatomical structures from patients. The images captured by these modalities are utilized for medical diagnoses, and play an important role these days.
Doctors in charge of the patients, such as internists and surgeries, forward orders to a radiological department, instructing a body site of inspection and the inspecting directions. So operators of the modalities, e.g. radiologists, capture medical images according the orders. However, the captured medical images do not always correspond to the site designed by the order. Because the position of anatomical structures differ a little between individual patients, it is difficult especially for tomographic modalities, such as CT scanners and MRI scanners, to adjust the imaging or scanning area to the ordered site.
In order to solve the above problem, CT and MRI scanners have been known from U.S. Pat. No. 5,514,957 and JPA 2005-245914, wherein prescanning is carried out in advance to main-scanning, and an anatomical image of a patient captured by the prescanning is displayed on a monitor, so that the operator defines a main scanning area on the displayed prescanning image by use of a cursor or the like. Then an image served for medical purpose is captured from the main scanning area. These prior arts allow the operator to define the main scanning area graphically on the monitor displaying the anatomical image of the patient, so the operator can define the main scanning area precisely while locating the anatomical structures of the patient.
Even with these prior arts that make prescanning, if the operator misreads the order, the main scanning area defined by the operator does not correspond to the body site of inspection as designated by the order. For example, if the operator mistakes that the site of inspection is abdomen while the order designates chest as the site of inspection, the main scanning area defined with reference to the prescanning image can precisely cover the patient abdominal region but does not correspond to the site of inspection.
JPA 2004-290329 discloses a modality that recognizes what sites are captured as a medical image by the CR scanner and judges whether the captured sites correspond to the site ordered to inspect. Because this prior modality makes the judgment on the formal medical image as captured by the main scanning, the operator must carry out the main scanning again if the captured sites do not correspond to the site of inspection. In that case, it takes extra time to retake the formal image again, and the patient is irradiated excessively by the repeated main scanning. Especially in the CT system, the radiological dosage by one cycle of main scanning is so much that the excessive amount of radiation to the patient due to the repeated main scanning is a serious problem.